NATURAL CLASSES. 71 



I. Series— EXOGENE8. 



I. Class. Driopses or Trees. Woody con- 

 centric leafy and branched, roots similar. Wood 

 hard. Shrubs are only small trees, and branches 

 of trees are shrubs. 3 Vines are climbing trees 

 or shrubs. 4 Bushes are the smallest or weak 

 shrubs commonly cespitose or with many stems 

 The orders may be. 



1. PoLOMES, (many frame) Branches, leaves 

 and often flowers assuming a compound form 

 either vertical or horizontal, — tSi/nophyles^ 

 leaves compound with articulated Iblioles. 

 Polytomes leaves united with folioles not articu- 

 lated. These are again divided in bipinnate, 

 pinnate, decompound &c. 



2. Trochomes, (wheeled) Branches, leaves 

 and often flowers verticillate around an axis, 

 or terminal — Rotules around stem or axis. 

 TJmhellites terminal wheel or umbel. 



3. DiPLOMES, (doubled) Br. leaves and fl. op- 

 posite to each other often jointed — Disticates, 

 in two rows. Decussates in four rows cross- 

 wise. 



4. Spiromes, (Spiraly) Br. leaves and fl. in a 

 spiral position around the stem or axis — Disti- 

 cales, spiral by 3. Alternates^ spiral by 4, Pen- 

 tales spiral by 5. Densales spiral by more than 

 5 and usually crowded imbricate. These are 

 seldom jointed. 



II. Class. Malaxyles or Anomalous Trees, 

 Wood hardly concentric, with few branches, 

 often articulate or no leaves : wood soft and 

 cellular ; roots similar — Very singular arboreal 

 form hardly noticed as yet off*ered by Carica, 

 Ephedra, Ficus, Viper, and other tropical trees, 



5. SicoMEs, Trees, with leaves and branches, 



